import pandas as pd
ppd.set_option('display.unicode.east_asian_width',True)
df=pd.DataFrame([['A','C','B'],['B','A','C'],['A','B','C'],['A','B','C']],cp;i,m['a','b','c'])
print('原始数据:\n',df)
print('按频数降序统计a列:\n',df.value_counts('a'))
print('按频数升序统计b列:\n',df.value_counts('b',normalize=True,ascending=True))
print('按频数降序统计所有列:\n',df.value_counts())
print('使用describe()函数统计所有列:\n',df.describe())